Photoshop Mix has been available as a free app from Adobe since June of 2014. It's not only a fun tool to play with, but it solves some important, sophisticated imaging needs without having to jump right into Photoshop itself.
Below are a few examples of how I've found Photoshop Mix useful.
A recent iPhone shot, before and after processing in Photoshop Mix. Becuse you can only add ONE look to an open image at a time in PS MIx, I've established a workflow where I add the effect, save the file as a new image, reopen the file and process with addtional looks. I keep going until I'm happy. For example, this image took a total of four renditions. You can learn a bit more by checking out my Work in Progress for the image below. I'm finding that I really like working with Selective looks, whee, using my finger, I paint on the effect in the desired areas.
I plan to experiment more with Photoshop Mix, working on Collage style imagery next. I hope you've found these examples helpful and that they inspire you to try things out in Photoshop Mix, too. The app is currently available for the iPad and iPhone.